The group of computer scientists from around the world cautions that "those deciding which age-based controls need to exist, and those enforcing them gain a tremendous influence on what content is accessible to whom on the internet." They add that "this influence could be used to censor information and prevent users from accessing services."

"Regulating the use of VPNs, or subjecting their use to age assurance controls, will decrease the capability of users to defend their privacy online. This will not only force regular users to leave a larger footprint on the network, but will leave a number of at-risk populations unprotected, such as journalists, activists, or domestic abuse victims." It continues: "We note that we do not believe that trying to regulate VPN use for non-compliant users would be any more effective than trying to forbid the use of end-to-end encrypted communication for criminals. Secure cryptography is widely available and can no longer be put back into a box."

"If minors or adults are deplatformed via age-related bans, they are likely to migrate to find similar services," warn the scientists. "Since the main platforms would all be regulated, it is likely that they would migrate to fringe sites that escape regulation." With data on everyone collected in order to restrict the activites of minors, data abuses and privacy risks increase. "This in itself increases privacy risks, with data being potentially abused by the provider itself or its subcontractors, or third parties that get access to it, e.g., after a data breach, like the 70K users that had their government ID photos leaked after appealing age assessment errors on Discord."

Instead of mandated age restrictions, the letter urges lawmakers to consider the dangers and suggest regulating social media algorithms instead. They also recommend "support for parents to locally prevent access to non-age-appropriate content or apps, without age-based control needing to be implemented by service providers."